Create an experiment for the learners to run - this could be planned in advance or could grow out of the students' engagement with the earlier activity.

It is important for students to explore the materials they are working with in their own way. The teacher's role is to observe, to be ready to ask questions to nudge a process along and to challenge facile assumptions. Sometimes it is enough to ask the students to explain why they have done one thing over another. Crucially, teachers should not ask with an answer in mind, but to be ready to hear the students’ thoughts.